Communications in Physics
EIT enhanced self-Kerr nonlinearity in the three-level lambda system under Doppler broadening
Dinh Xuan Khoa, Le Van Doai, Pham Van Trong, Tran Manh Cuong, Vu Ngọc Sau, Nguyen Huy Bang, Le Nguyen Mai Anh
Abstract
Using density-matrix theory, an analytical expression of the self-Kerr nonlinear coefficient of a three-level lambda EIT medium for a weak probe light is derived. Influences of the coupling light and Doppler broadening on the self-Kerr coefficient are investigated and compared to experimental observation with a good agreement. The self-Kerr nonlinearity is basically modified and greatly enhanced in the spectral region corresponding to EIT transparent window. Furthermore, sign, slope, and magnitude of the self-Kerr coefficient can be controlled with frequency and intensity of the coupling light and temperature. Such controllable Kerr nonlinearity can find interesting applications in optoelectronic devices working with low-light intensity.